As a young reporter, I once expressed shock at how routinely and reflexively government officials lied to the press. A savvy newspaper vet who overheard me just smiled and told me not to take it personally.

“Why shouldn’t they lie to you?” the late, great Murray Kempton asked. “They lie to themselves all the time.”

His observation came back to me as I read about President Obama’s trip to Asia. He’s going, the White House says, to tell our allies face to face that America is committed more than ever to their security and prosperity.

In ordinary times, the trip and the promise would mean a great deal to the Japanese, South Koreans and Filipinos nervous about trade and China’s aggressive military moves. But these are not ordinary times and Barack Obama is no ordinary president.

Consider that it’s been three years since Obama first declared a “pivot” to Asia as part of a strategic rebalancing of American interests, but the promise proved hollow. Asia is not alone in feeling misled.

Ask the Syrians about Obama’s promise to act if their government crossed his “red line” and used chemical weapons. Or ask Israelis, Saudis, Jordanians and others in the Mideast about Obama’s pledge that America would never allow Iran to get a nuclear weapon. Or ask Ukrainians about his pledge that we will stand with them as they fight for democracy against Vladimir Putin.

OK, the last promise wasn’t so much a lie as a sick joke. It turns out that by “help,” Obama meant we would send military rations and warm socks, but no weapons or intelligence to help Ukraine’s outgunned army.

If that were all the president had done to cause mistrust, it would be enough. But it’s not just foreigners who have been misled.

Worst of all, Obama lies to his fellow Americans. All the time.

Most infamous was his claim that, under ObamaCare, “if you like your doctor, you can keep your doctor.” Not far behind was his insistence, repeated for weeks during his re-election campaign, that the terror attack on Benghazi was the spontaneous result of a protest against an anti-Muslim video.

Assorted promises to lift the economy, unite the country, get to the bottom of the IRS scandal and be transparent are so routinely violated that they hardly register as false anymore.

Still, the overall impression that Obama is President Pinocchio is catching up to him. A Fox News poll showed that over 60 percent of American voters think he intentionally misleads them about important matters some or most of the time.

A whopping 37 percent think he lies “most of the time,” while another 24 percent say he lies “some of the time.” Twenty percent of voters say “only now and then” and 15 percent “never.”

Abraham Lincoln, supposedly an Obama hero, warned about the corrosive effect of failing to be honest. As he famously put it, “You can fool some of the people all of the time, and all of the people some of the time, but you cannot fool all of the people all of the time.”

That more or less sums up where we are, or, rather, where Obama is. Nearly six years in office, much of the world is united only in not trusting his word.

Even for those inclined to believe, as Murray Kempton did, that a public lie often starts with self-deceit, the impact is enormous. Although it’s possible Obama intended to stand up to Syria’s Assad, or to Iran’s mullahs, or to Putin or China, the fact that he hasn’t is all that matters.

The result is that, while the United States remains the lone superpower, we are not feared by the world’s most malevolent forces.

We are witnessing the making of a tragic history. The fact that America’s leader lacks credibility among friend and foe alike is creating peril without precedent. Absent a sudden stiffening of spine and a president whose word is his bond, the world is heading toward a catastrophe.

That’s the truth.

Hey, Bill, just do the math

Mayor Bill de Blasio’s bid to squash the charter-school movement never made sense, but new data on students underscores how his policy contradicts his goal of tackling educational inequality.

According to the Independent Budget Office, whites make up only 3 percent of charter-school students, while blacks and Latinos together account for over 90 percent.

The mayor’s stance is confounding because the best charters show that poor, nonwhite children can match or surpass whites on standardized tests. In other words, the dream of closing the racial achievement gap is being realized at the schools de Blasio opposes.

If he were a Republican, he’d be called a racist.

It stands to (T) reason

The argument that liberalism is a disease is unfair — to diseases! Take two overheated responses to my column saying the Pulitzer Prize board made treason cool by rewarding news organizations that published Edward Snowden’s stolen documents.

The writers praise Snowden for revealing surveillance secrets, but can’t stop there. Their politics requires them to make ridiculous comparisons and wish that I suffer for daring to disagree with them.

One writer, identifying himself only as Matthias, claims our government is worse than “what the Stasi inflicted on East Germans,” then adds a favorite lefty cliché with a twist: “I despise what you say but will defend to the death your right to say it, but with the hope you burn in hell.”

The other writer, named only JT, calls me a “son of a bitch who shills for the nazi police state!” After more profanity and homophobic slurs, he adds, “I hope you die soon and VERY soon very very painfully!”

The kooks make my case that the Pulitzer board gave comfort to anti-Americans. People filled with such hatred for their fellow citizens cannot be trusted to protect our nation.

Blood on Al’s hands

Reader Frank DeSanna goes back to the 1995 arson fire at Freddie’s Fashion Mart, which killed seven workers, to argue that Al Sharpton should never be celebrated. “I am a firefighter in Harlem and I will never forget the fire and Sharpton’s role in it,” he writes. “Sharpton’s anti-Semitic speech inspired Roland Smith to commit that heinous crime. When will Sharpton be held accountable for the deaths, for which he never took any responsibility?”

Viv’s weird Tex message

Ultra-liberal Council Speaker Melissa Mark-Viverito is confused. She denounced a visit by Texas Gov. Rick Perry before it happened, saying his politics are “something New Yorkers will overwhelmingly and easily reject.”

But Perry didn’t come to Gotham to sell himself to blue-state voters. He came to sell Texas as a low-tax, pro-business, pro-family state where even Democrats might want to live and create jobs.

Perhaps that’s why Mark-Viverito lashed out at Perry. Like a lawyer who has neither the facts nor the law on her side, all she can do is pound the table.